Flow Cytometry Facility (Larry W. Arnold, Ph.D., Facility Director) The Flow Cytometry Facility provides Cancer Center investigators with access to all aspects of flow cytometry technology, including state-of-the- art instrumentation, data acquisition, high speed cell sorting, data analysis, preparation of publication-quality data presentation, and consultation. Facility staff also train users to prepare samples and operate the analytical flow cytometers (B-D FACScans) and one sorting flow cytometer (Cytomation MoFlo), which has added high-speed cell sorting capabilities to the facility array of services. Over the past year, there has been a large increase in flow cytometry use, with a significant increase in sorting as the MoFlo became operational. In fiscal year 1997-1998, the facility charged for 2,851 hours of use. Cancer Center members accounted for more than three-fourths (79%) of all this use, while the Center Core Support Grant (CCSG) constituted just under one-half (49%) of the budget. All of the Cancer Center use was by investigators with peer- reviewed funding. In the coming year, CCSG support of $75,992 is requested (43% of total budget), primarily to support the Facility Director (35%) and technician (75%), who have played a central role in promoting increased use overall as well as of sorting flow cytometry. Because service contracts for flow cytometry equipment are considerable, CCSG support for one-third ($20,000) of the facility's service contract costs is also requested.